June 2019 meeting

Dave Nordling, Secretary, Reaction Research Society


The RRS held its monthly meeting on Friday, June 14, 2019, at the Ken Nakaoka Community Center in Gardena, CA. We had several discussion topics on the agenda, but we had a last minute confirmation of a special guest. Terry Price, a nationally recognized expert in composite materials, gave the society an overview of composites used in many industries including aerospace.

Terry Price, retired consultant and formerly of Cerritos College and the Center for Composites Training
Terry describes the processes involved in composite manufacture. Our special guest (seated left) was Dennis Lord, President of the Experimental Aircraft Association, Chapter 96, at the Compton-Woodley Airport.
Terry answers questions from our membership, Drew Cortopassi, Steve Majdali and Larry Hoffing.

Terry’s presentation lasted for nearly the entire meeting, but no one seemed to mind. It’s a fascinating subject with many applications. Those specific to rocketry would be composite over-wrapped pressure vessels and tubular composite air-frames.

RRS treasurer, Chris Lujan, and RRS vice president, Frank Miuccio, engrossed in the presentation by Terry Price.

Another one of our guests at the meeting was Dennis Lord who is president of the Experimental Aircraft Association, Chapter 96 (EAA 96). Dennis came to help promote the EAA and let us know that the National Transportation Safety Board (NTSB) was going to make a presentation at their meeting on Saturday, June 15th. The EAA meets every 3rd Saturday of each month.

At the very end of the meeting, Osvaldo did bring up a few topics, mainly about the past Mojave Test Area event we had with UCLA on June 1st, and the next event we’re planning with LAPD CSP on July 13th. The RRS has had some issues with the MTA site being left untidy by our guests. The RRS would like to remind our visitors to please pick up their trash before they depart.

Our concrete test pad with male anchor bolts protruding. The RRS is thinking of making a cleaner simpler interface at this part of our testing site.

Also, the use of male anchor bolts, which are commonly available at hardware stores like Home Depot, while convenient to the builder make for a terrible tripping hazard as these bolts remain planted for years. As we are getting more users at the MTA site, the number of irregular protruding bolts is growing and becoming irksome. The best solution is to work with the RRS before making changes to our concrete and using female anchor bolts which may require ordering in advance. The RRS has discussed making a common ground interface for all users to adapt their horizontal thrust stands. Although some of our past users may have to redrill their bolt patterns in their equipment, in the long run, it will be simpler and better for all. There will be more on this subject in the coming months as the RRS is pursuing several renovation projects to improve the MTA.

One of the last topics before we adjourned late on that evening was a new payload being made by returning RRS member, John Krell. Nearly all of our RRS standard alphas, flown by the dozens several times a year, fly with empty payload tubes. There has been much conjecture on the apogee height and burnout velocity of an RRS standard alpha micrograin rocket. Best estimates are that they are subsonic and may be reaching heights of nearly one mile. To answer these questions, a simple payload to measure barometric pressure and record the acceleration of the swift alpha.

John Krell describes the avionics payload he’s been working on to fly in an RRS standard alpha rocket.

John’s prototype is only at the breadboard stage, but he has identified the right parts for the first flight prototype using an Arduino Nano microprocessor and a 100G rated accelerometer as best estimates of the RRS alpha acceleration are at least 50G’s.

A closeup view of the prototype payload consisting of a barometer, accelerometer, and microcomputer for data acquisition.

Our next meeting will be July 12, 2019. We will discuss the topics we couldn’t cover this month including the RRS liquid rocket projects and the RRS social media improvements including adding a better calendar feature for the growing number of events we’re having.

Our next launch event at the MTA will be July 13th with the LAPD CSP.


MTA launch event, 2019-06-01

by Mitchell Spearrin, Associate Professor of Mechanical and Aerospace Engineering, UCLA


On Saturday, June 1, the Reaction Research Society (RRS) hosted the UCLA Aerospace Engineering senior design (MAE 157A) class at the Mojave Test Area (MTA) I have been teaching this class for three years which involves the design, analysis, manufacturing, testing, and finally launch of mid-power solid and hybrid rockets. Approximately 50 students attended this event at the end of the Spring Quarter of 2019 with RRS president, Osvaldo Tarditti, serving as pyro-op.

UCLA students prepare their rockets in the loading bays.
UCLA students prepare their rockets for launch.

Twelve rockets were fabricated by students teams of four or five students each over a 9-week period, eleven of which were launched successfully on Saturday. The launches included nine solid composite rockets in the E and F-size classes. Two of the rocket designs involved a staged design, with retro-exhaust ignition for the second stage.

UCLA model rocket on the wooden cross rail launcher
A well-timed photograph of the UCLA model rocket leaving its rail launcher.

Two hybrid rockets using polyvinyl chloride as fuel and nitrous oxide as oxidizer were launched on the RRS 20-foot 1515 rail launcher. The hybrids were fully fabricated by students at UCLA including the propulsion systems. All rockets included payloads of altimeters, cameras, and a hard-boiled egg with the design competition aiming for altitude and reusability upon recovery.

UCLA students prepare their custom-built hybrid rocket on the RRS 20-foot rail launcher.

With the assistance of Osvaldo’s ATV, all rockets were successfully recovered, though only a few were returned with an unbroken egg.

Osvaldo Tarditti supervised the event and made down-range tracking of the UCLA rockets much easier with his all-terrain vehicle (ATV).

100 Years Ago: A Method of Reaching Extreme Altitudes

Dave Nordling, Secretary, Reaction Research Society


The pioneering theoretical and experimental work that formed the basis for the modern practical liquid rocket was published 100 years ago today.

A Method of Reaching Extreme Altitudes, by Robert Hutchings Goddard (1882-1945), was published by the Smithsonian Institution, on May 26, 1919. Considered the father of American rocketry, Goddard developed the theory of his work while at Princeton University in 1912-1913 with experiments undertaken during 1915-1916 at Clark University.

http://www2.clarku.edu/research/archives/pdf/ext_altitudes.pdf

This 79-page paper described a series of practical experiments using nitrocellulose “smokeless” powder combusted within an enclosed chamber through a de Laval nozzle both in the ambient environment and under vacuum conditions. This paper also included mathematical derivations to develop a theory of rocket action taking in account air resistance and gravity with the goal of determining the minimum initial mass necessary for an ideal rocket to deliver a final mass of one pound to any desired altitude.

In his research, Goddard sought to devise a practical means to send instruments above the range of sounding balloons (about 20 miles) to explore the upper atmosphere. What makes this work fascinating is how much was known at the time of his paper’s publication versus how much was yet to be learned and become common knowledge in our time. Very little was known about the nature of the upper atmosphere in 1919. Yet, the basic concept of a rocket with a restrictive nozzle was known for centuries in the Chinese civilization and later in Europe with the 19th century British Congreve rockets.

In this scientific work, Goddard meticulously lays out his plan of research and the incremental progress he made to verify each of his claims. Most significant is his first conclusion on page 34 that his experiments in air and in vacuum prove that the propulsive force from a rocket is really based on a jet of gas having an extremely high exhaust velocity and is NOT merely an affect of reaction against the air.

Goddard’s work did not receive much funding during his lifetime. His work in rocketry even invited the ignorant criticism of the New York Times and others in the public which had a profound affect on Goddard in his lack of willingness to collaborate even until his death in 1945. In all fairness, it should be noted that the New York Times did see fit to offer an apology to Goddard 24 years after his death and only 50 years ago (in 1969) in the weeks before the Apollo 11 flight that landed the first two men on the moon by a multi-stage rocket operating quite well in the vacuum of space without a media for the vehicle to react against.

Air & Space Magazine, The Misunderstood Professor

by Frank H. Winter, May 2008

https://www.airspacemag.com/space/the-misunderstood-professor-26066829/

Goddard was awarded two patents in 1914, one for a multi-stage rocket and one for a liquid-fuel rocket. Considered an iconic work of 20th century science, all rocketry enthusiasts, students and professionals owe themselves the privilege of reading Dr. Goddard’s 1919 monograph which would lead to the first successful test of a liquid rocket flight in 1923 and the first successful liquid rocket flight on March 16, 1926 in Auburn, Massachusetts.

Goddard’s early discoveries included the determination that fins on a rocket by themselves were not sufficient to stabilize a rocket in flight. Goddard’s inventions included movable vanes to vector the rocket exhaust stream in flight and a gyroscope-based control system to effectively guide a rocket in flight.

Although relatively unappreciated in his home country, Goddard’s work was noticed by the Germans and in years later leading to their own rocket development program leading to the V-2 ballistic missile used to terrifying effect during the latter portion of the Second World War. During the Cold War, the V-2 was the heritage of the first rockets by the first space-faring nations.


https://en.wikipedia.org/wiki/Robert_H._Goddard